Is atheism a scientific perspective?

[Angrboda]

(emphasis mine)

These are radically different claims.  The first is true but unremarkable.  The second would be true if you'd actually shown other causes are insufficient, but you haven't done that.  All you've done is whine about improbabilities and use undefinable terms like "specified information."  Showing that the exact process of abiogenesis responsible for life on this planet is unknown doesn't advance the proposition of intelligent design.  It's just a fallacious argument.  The fact is that nobody has been able to create a filter that can reliably separate out those things that were designed from those that weren't designed.  In its absence, we have a bunch of arguments from ignorance and arguments from incredulity.  If this is the best that the ID movement can produce, it is a very poor showing.  More, because it's a possibility that humans evolved their ability to design things, you haven't even shown that design points to a non-natural process.  That's a complete failure for those hoping that design is the magic bullet that points to God.

You're right, the claim is that it is the only known cause, not that it is the only cause. I should have been more careful with that. Information is defined as that which is conveyed by a sequence of things. The specified part is indicating that the information is used to accomplish a desired function.

And you have no way to define that rigorously. This is a backward definition. It implies design in the way you've formulated it, which makes it nothing more than begging the question. Can you use it in a sentence? Show how fairy rings do not contain specified information in a way that doesn't implicitly reference design.

Couple that with the fact that the sequence is highly irregular, and you start to see how intelligence is a good candidate.

This is mere complexity and is back to the argument that it couldn't arise by pure chance. Since evolutionary processes have already been demonstrated to produce greater complexity from simpler origins, it makes some form of evolutionary process an equally viable candidate.

This is why it is essential to compare the competing hypothesis for the origin of information. When the others fail, and only one remains, we can conclude that the remaining one is the only known cause. We can and should look for other causes, but that doesn't change the fact that only one possible explanation has been identified despite rigorous searching.

Rigorous searching doesn't change this from an argument from ignorance. It's unsound to conclude that the cause was intelligence until all possible alternative causes have been explored. Not just 'known' causes but all possible. This you've failed to do. That's why you have all this talk about known causes, instead of a positive argument for design. If you had a positive argument, you'd use it. Therefore an argument from ignorance is the only known argument for intelligent design.

And the intelligent design advocates have been working hard to develop methods of design detection. William Dembski has worked on this issue.

The same could be said for abiogenesis. It means little without any actual results. Despite "rigorous searching" no positive argument for design has been developed.

You're right that it doesn't necessarily point to God, and that is why the ID community does not attempt to identify the designer(s).

This is disingenuous twaddle. We all know your end game. You're not fooling anyone.